激光及涂层表面处理对氧化锆陶瓷粘接强度的影响

Effect of laser and coating surface treatment on the bond strength of zirconia ceramics

摘要

目的 探讨Er: YAG激光、Nd: YAG激光及硅锆涂层处理氧化锆陶瓷表面对其粘接强度的影响。 方法 用粉末压片机制作直径为18 mm、厚度为1.5 mm的氧化锆预烧结圆形瓷片，按照伪随机数字表法随机分为5组，分别接受不处理烧结（空白对照组）、烧结后氧化铝颗粒喷砂（喷砂组）、烧结后Er: YAG激光照射（Er: YAG激光组）、烧结后Nd: YAG激光照射（Nd: YAG激光组）、硅锆涂层后烧结（硅锆涂层组）表面处理，用树脂粘接剂粘接氧化锆陶瓷与复合树脂柱，用万能测试机进行剪切强度测试，体式显微镜下观察并记录断裂破坏模式，粗糙度测量仪测量瓷片表面粗糙度，扫描电子显微镜下观察表面微观形貌，能谱仪分析表面元素组成。 结果 剪切粘接强度测试结果表明，硅锆涂层组的剪切粘接强度高于其余各组，差异有统计学意义（P<0.05）；喷砂组与Er: YAG激光组的粘接强度差异无统计学意义（P>0.05），但均高于Nd: YAG激光组，差异有统计学意义（P<0.05）。粗糙度测量结果表明，硅锆涂层组的表面粗糙度高于其余各组，差异有统计学意义（P<0.05）；喷砂组、Er: YAG激光组和Nd: YAG激光组的表面粗糙度差异无统计学意义（P>0.05），但均高于空白对照组（P<0.05）。扫描电子显微镜下观察可见，喷砂组表面可见无规则深浅不同的划痕，Er: YAG激光组表面可见激光作用形成的较大凹坑，较大凹坑中可见散在较小的孔洞，氧化锆晶体结构消失，取而代之的是局部熔融形成的相对平整表面，表面可见大量裂纹。Nd: YAG激光组表面可见激光作用区形成凹坑，凹坑表面可见大量裂纹形成。硅锆涂层组表面可见较为复杂的多孔结构，可见大量“小岛样”结构，“小岛样”结构表面及其周围沟壑内可见大量氧化锆晶粒，晶粒间存在大量微小孔隙。空白对照组、Er: YAG激光组及Nd: YAG激光组表面仅有Zr、O、Y元素，喷砂组表面可见Al元素存在，硅锆涂层组可见较高比例的Si元素。 结论 Er: YAG激光及Nd: YAG激光处理氧化锆陶瓷表面可使其粗糙度增加，提高与树脂粘接剂间的粘接强度。硅锆涂层处理能增加氧化锆表面粗糙度和粘接强度，且效果优于喷砂及激光处理。

Abstract

Objective This study aims to investigate bond strength between zirconia and resin cement through surface treatments with Er: YAG laser, Nd: YAG laser, and Si-Zr coating. Methods Seventy-five round pre-sintered zirconia discs with a diameter of 18 mm and a thickness of 1.5 mm were prepared by a powder compactor. Fifty discs were randomly divided into five groups of 10 discs each and were subjected to five surface treatments: no treatment (control group), sandblasting with alumina particles (sandblasting group), Er: YAG laser treatment (Er: YAG laser group), Nd:YAG laser treatment (Nd: YAG laser group), and Si-Zr coating treatment (Si-Zr coating group). The discs were then bonded to composite resin columns with resin cement. The shear bond strength of each group was tested with a universal tester. Roughness tester, scanning electron microscope (SEM), and energy dispersive spectroscopy were used to analyze surface performance. Results The bond strength of the Si-Zr coating group was higher than that of the remaining groups (P<0.05). The difference in bond strength between the sandblasting group and the Er: YAG laser group was not statistically significant (P>0.05), but both of them had higher bond strength than the Nd: YAG laser group (P<0.05). The Si-Zr coating group had the highest surface roughness (P<0.05). The surface roughness of the sandblasting, Er: YAG laser, and Nd: YAG laser groups was higher than that of the control group (P<0.05), but the difference among the three groups was not statistically significant (P>0.05). SEM observations showed irregular scratches on the surface of the sandblasting group and large pits with holes on the surface of the Er: YAG and Nd: YAG laser groups. In the Er: YAG laser group, the crystal structure was replaced by a smooth surface with a large amount of microcracks due to partial melting. Complex porous structures that comprised “island-like” structures and mass pores among the grains were observed on the surface of the Si-Zr coating. Only Zr, O, and Y were detected on the surfaces of the control, Er: YAG laser, and Nd: YAG laser groups. Al was found on the surface of the sandblasted group, and a higher proportion of Si was detected on the surface of the Si-Zr coating group. Conclusion Er: YAG laser and Nd: YAG laser treatment on the zirconia ceramic surface could increase roughness and improve the bond strength to resin cement. Si-Zr coating treatment is an effective alternative for increasing the roughness and bond strength of zirconia surface and is superior to sandblasting and laser treatments.

关键词

氧化锆 / 表面处理 / 粘接强度 / 激光 / 涂层

Key words

zirconia / surface treatment / bond strength / laser / coating

Author summay

杜桥，主治医师，硕士，E-mail：[e-mail]